Battery Cell Balancing Circuit With Common Resistor Switching
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Solution Overview
Problem
Existing battery management systems face challenges in increasing the speed of cell balancing operations in lithium-ion batteries, leading to inefficiencies in charging and discharging due to voltage and aging differences among battery cells.
Innovation Solution
A battery management apparatus with balancing resistors, a common resistor, resistive switches, and a controller that calculates balancing times and controls the resistive switches to selectively connect balancing resistors with the common resistor for targeted cell balancing, thereby increasing the speed of cell balancing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional cell balancing techniques are used, then all battery cells can be managed, but the cell balancing speed is slow due to individual balancing operations
Solution Approach 1:
The patent merges multiple individual balancing operations into a single group balancing operation by connecting multiple battery cells in parallel to share a common balancing resistor. This allows simultaneous balancing of multiple cells, significantly increasing the cell balancing speed and reducing the time loss during charging/discharging cycles.
Solution Approach 2:
The patent dynamically switches between individual balancing mode and group balancing mode based on real-time voltage differences among battery cells. The controller adjusts the balancing strategy adaptively, enabling the system to optimize balancing speed while maintaining effectiveness across different operational states.
2Measurement precision
If individual balancing operations are performed for each battery cell, then precise voltage control is achieved, but the overall balancing process becomes time-consuming
Solution Approach 1:
The patent segments the balancing process into two distinct modes: individual balancing for precise voltage control of specific cells, and group balancing for rapid simultaneous balancing of multiple cells. The controller selectively applies each mode based on the voltage difference thresholds, achieving both precision and speed in different scenarios.
Solution Approach 2:
The patent changes the balancing parameters dynamically by adjusting which cells are connected to the common balancing resistor based on their voltage levels. This parameter adjustment allows the system to switch between precise individual control and rapid group balancing, optimizing both voltage control precision and operation duration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution quickly addresses cell imbalance by enhancing the speed of the cell balancing process, ensuring that all battery cells are fully charged or discharged efficiently, thereby improving the overall performance and longevity of lithium-ion batteries.
Implementation Method 1
a plurality of balancing resistors respectively connected to a plurality of battery cells, a common resistor connected in parallel to the plurality of balancing resistors, a plurality of resistive switches connected between the plurality of balancing resistors and the common resistor
Data Source
AI summary
A battery management apparatus according to an embodiment can include a plurality of balancing resistors respectively connected to a plurality of battery cells, a common resistor connected in parallel to the plurality of balancing resistors, a plurality of resistive switches connected between the plurality of balancing resistors and the common resistor, and a controller for calculating balancing times of the plurality of battery cells and control operations of the plurality of resistive switches based on the balancing times.